Partilhar via


Code Snippets

Note

This article applies to Visual Studio 2015. If you're looking for the latest Visual Studio documentation, see Visual Studio documentation. We recommend upgrading to the latest version of Visual Studio. Download it here

Code snippets are small blocks of reusable code that can be inserted in a code file using a context menu command or a combination of hotkeys. They typically contain commonly-used code blocks such as try-finally or if-else blocks, but they can be used to insert entire classes or methods.

Expansion Snippets and Surround-With Snippets

In Visual Studio there are two kinds of code snippet: expansion snippets, which are added at a specified insertion point and may replace a snippet shortcut, and surround-with snippets (C# and C++ only), which are added around a selected block of code.

An example of an insertion snippet: in C# the shortcut tryf is used to insert a try-finally block:

try
{

}
finally
{

}

You can insert this snippet by clicking Insert Snippet in the context menu of the code window, then Visual C#, then type tryf, then TAB, or you can type tryf and press TAB + TAB.

An example of a surround-with snippet: in C++ the shortcut if can be used either as an insertion snippet or as a surround-with snippet. If you select a line of code (for example return FALSE;), and then click Surround With, then if, the snippet is expanded around the line:

if (true)
{
    return FALSE;
}

Snippet Replacement Parameters

Snippets can contain replacement parameters, which are placeholders that you must replace to fit the precise code you are writing. In the previous example true is a replacement parameter, which you would replace with the appropriate condition. The replacement you make is repeated for every instance of the same replacement parameter in the snippet.

For example, in Visual Basic there is a code snippet that inserts a property. Click Insert Snippet on the context menu of the code window, then Code Patterns, then Properties, Procedures, Events, then Define a property. The following code is inserted:

Private newPropertyValue As String
Public Property NewProperty() As String
    Get
        Return newPropertyValue
    End Get
    Set(ByVal value As String)
        newPropertyValue = value
    End Set
End Property

If you change newPropertyValue to m_property, then every instance of newPropertyValue is changed. If you change String to Int in the property declaration, then the value in the set method is also changed to Int.

Code Snippet Manager

You can see all the code snippets that are currently installed, plus their location on disk, by clicking Tools/Code Snippets Manager. Snippets are displayed by language.

You can add and remove snippet directories with the Add and Remove buttons in the Code Snippets Manager dialog. To add individual code snippets, use the Import button.

See Also

Walkthrough: Creating a Code Snippet How to: Distribute Code Snippets Best Practices for Using Code Snippets Troubleshooting Snippets Visual C# Code Snippets Visual C++ Code Snippets Code Snippets Schema Reference